1.1 Drive motors are a critical component in the new energy industry, with permanent magnet synchronous motors now dominating the market.
Drive motors represent a vital link in the new energy vehicle supply chain. The motor drive control system serves as the primary executive mechanism during vehicle operation, making the drive motor and its control system one of the core components (battery, motor, electronic control) of new energy vehicles. Its drive characteristics directly determine key performance metrics such as hill climbing, acceleration, and speed, establishing it as an essential part of electric vehicles. Taking the mainstream permanent magnet synchronous motor as an example, the motor primarily consists of a stator, rotor, and mechanical structure, with the stator and rotor being the key components.
Permanent magnet synchronous motors and AC induction motors have become the mainstream choices in the passenger vehicle sector. The “permanent magnet” in permanent magnet synchronous motors refers to the incorporation of permanent magnets during rotor manufacturing, which further enhances the motor's performance. This is also the distinction between permanent magnet synchronous motors and AC induction motors. The term “synchronous” refers to maintaining a constant speed between the rotor and the frequency of the stator winding current. In AC induction motors, the rotor constantly “chases” the speed of the stator's rotating magnetic field. To generate induced current by cutting magnetic flux lines, the rotor's speed is always slower than the stator's rotating magnetic field, resulting in asynchronous operation—hence the name asynchronous induction motor.
Permanent magnet synchronous motors and AC induction motors each have their own strengths. Permanent magnet synchronous motors inherently offer advantages such as high torque density, high power density, high efficiency, and excellent speed regulation performance. Combined with their compact size and light weight, they are highly advantageous. However, they are not without drawbacks. Aside from cost issues stemming from raw materials, they suffer from magnetic decay at high temperatures. This is why small and medium-sized pure electric vehicles cannot sustain long periods of high-speed cruising. In contrast, AC induction motors offer simpler structures, higher reliability, and superior high-speed and acceleration performance. This makes them favored by performance-oriented electric sports cars and mid-to-large SUVs like the Tesla Model S, Model X, and NIO ES8. However, their drawbacks include lower torque density, power density, and efficiency density, coupled with bulkier size, heavier weight, and higher heat generation. Overall, it can be understood that EVs equipped with permanent magnet synchronous motors generally offer better range, while those with AC induction motors deliver superior acceleration performance.
Permanent magnet synchronous motors hold nearly 95% of China's drive motor market share. Leveraging China's advantage in rare earth resources, these motors feature high power density, peak efficiency, compact size, light weight, diverse structures, and broad applicability. Consequently, their installed base in China has grown rapidly. By November 2021, domestic installations of permanent magnet synchronous motors reached 2.69 million units, accounting for 94% of the market share and establishing a dominant position in the new energy drive motor sector.
1.2 Flat-Wire Winding Motors Offer Significant Advantages and Substantial Technical Improvement Potential
We identify flat-wire winding (hair-pin motor) as a key technological trend in drive motors. The overarching goal is to enhance efficiency and power density while reducing size and weight. Flat-wire wound motors feature stator windings made from flat copper wire, shaped into hair-pin configurations before being inserted into stator slots, with the ends welded together. By utilizing flat copper wire with a larger cross-sectional area, these motors achieve higher slot fill rates. This results in advantages such as high power/torque density, high pinout density, and superior heat dissipation. Additionally, flat-wire motors facilitate automated production, meeting the stringent consistency requirements of the rapidly expanding new energy passenger vehicle market. However, widespread adoption faces challenges including low yield rates, limited maximum speeds, difficulties in standardization, and patent barriers.
Flat wire achieves higher slot fill rates, and its high energy conversion efficiency leads to battery cost savings. Motor power is positively correlated with copper content; a 20-30% increase in copper wire filling within the same volume implies a potential 20-30% boost in output conversion power. Flat wire motors achieve a pure copper slot fill rate of 70%, compared to only about 40% for traditional round wire. Since 65% of motor energy loss stems from copper resistance, flat wire motors require shorter copper wire than equivalent-power round wire motors. This reduces winding resistance and copper loss, resulting in higher conversion efficiency. Furthermore, in congested urban driving conditions (low RPM, high torque), flat-wire motors operate 10% more efficiently than round-wire counterparts. The higher slot fill rate expands the efficiency zone, increasing WLTP range in real-world driving tests. This allows for reduced battery capacity while maintaining equivalent range, effectively lowering overall vehicle costs by 15%.
Flat wires offer superior heat dissipation, enhancing high-temperature performance. Due to tighter conductor contact, reduced slot voids, and improved thermal conductivity and heat dissipation coefficients, thermal transfer between windings at high slot fill rates is 1.5 times greater than at low fill rates. Reduced AC resistance lowers heat generation at low-to-medium speeds, decreasing stator temperature rise by 18% compared to round wire. It also reduces thermal resistance within slots for better heat transfer. The high slot fill rate delivers greater power and torque capacity, improves stator slot cooling, and lowers thermal resistance within slots, reducing temperature rise by approximately 8–12%. Under lower temperature conditions, the vehicle achieves superior acceleration performance.
Flat-wire motors deliver higher power density and stronger overall vehicle dynamics. Their high slot fill rate increases torque density, reduces effective volume, boosts torque output, and enhances power and power density (e.g., SAIC's second-generation EDU high-power hairpin motor achieves a 20% power density increase). This strengthens torque output capability, further elevating power density and overall vehicle performance. Round-wire motors, with a power density level of approximately 3.5 kW/kg, fail to meet the “13th Five-Year Plan” requirement of 4.0 kW/kg. In contrast, flat-wire motors from leading manufacturers achieve power densities around 5 kW/kg, making flat-wire technology an inevitable future trend. Additionally, flat-wire motors leverage their larger end conductor gaps to allow cooling oil to directly penetrate the winding ends. This absorbs heat from each conductor, reducing motor winding temperatures by over 68%, significantly boosting both power density and torque density levels.
Flat-wire motors produce lower electromagnetic noise, resulting in quieter vehicles. Flat-wire motors exhibit higher conductor stress and winding rigidity, resulting in improved armature stiffness and increased elastic modulus. This alters the object's modal characteristics, favoring impedance resonance and suppressing armature noise. Furthermore, cogging torque is an inherent issue in permanent magnet motors. While it does not increase or decrease the motor's average effective torque, it causes speed fluctuations, motor vibration, and noise (NVH). Flat wire windings are inserted through the core ends, eliminating slot insertion. With relatively smaller slot dimensions in electromagnetic design, cogging torque can be reduced by 19% and NVH by 12%, further suppressing electromagnetic noise.
The compact size of flat wire enables high integration efficiency, aligning with the trend toward multi-in-one electric drive systems. Flat wire achieves higher slot fill rates, employs more advanced winding methods, and facilitates easier trimming. The winding end height can be reduced by approximately 15%, allowing for greater compression and resulting in a smaller motor volume for the same power output. Compared to traditional round-wire copper windings, the effective volume of flat-wire cores decreases, allowing for a 15% reduction in axial length, a 10% reduction in outer diameter, approximately 20% less copper usage, and a 10% reduction in overall weight. This aligns with current trends toward motor lightweighting and miniaturization.
1.3 Mainstream Automakers Adopt Flat-Wire Motors, Driving Rapid Growth in Market Penetration
Among the top 15 best-selling new energy vehicle models in 2020, only select models like the ORA R1, Li ONE, and NIO ES6 adopted flat-wire motors. The penetration rate of flat-wire motors in 2020 was less than 10%. Combined with the overall new energy vehicle penetration rate of 5.4%, the comprehensive penetration rate of flat-wire technology remained below 1%.
Since 2021, the penetration rate of flat-wire motors has accelerated. Tesla and GAC Motor have adopted flat-wire motors, BYD's DMI system uses them across its lineup, and new models from SAIC and Great Wall have also switched to flat-wire motors. Among the top 40 models by monthly sales volume in the first 11 months of 2021, 16 models featured flat-wire windings. Our calculations indicate that the penetration rate of flat-wire motors among the top 40 models reached 31.1%. Given that the top 40 models accounted for 76.6% of total passenger vehicle sales in November, the current penetration rate of flat-wire motors is estimated to exceed 23.9%. (Premium models with lower sales volumes exhibit even higher penetration rates.)
Upcoming potential blockbuster models like the ET5, ET7, IM Motors, and Zeekr also adopt flat-wire motors. Given the advantages of high power density, superior energy conversion efficiency, and excellent heat dissipation, flat-wire motor penetration is expected to rise rapidly over the next 3-5 years.
1.4 Dual-Motor Configurations Gain Traction; Global Drive Motor Market Projected to Reach RMB 74 Billion by 2025
Performance upgrades for new energy vehicles are imminent, driving increased adoption of dual-motor layouts. Currently, mid-to-high-end models typically offer both single-motor and dual-motor variants. Single-motor configurations are common in base-trim models, with pure electric vehicles featuring front- or rear-mounted motors and hybrid models generally employing front-mounted motors. Dual-motor setups are typically reserved for high-trim models, spanning pure electric, plug-in hybrid, and range-extended variants, each deploying one motor at the front and rear. With the rapid rise in new energy vehicle penetration and growing consumer acceptance of electric vehicles, we anticipate that performance upgrades will drive demand for all-wheel-drive dual-motor and even triple-motor variants. The market share of dual-motor models is expected to increase further.
The new energy vehicle market is booming, fueling rapid growth in drive motor installations. Benefiting from the domestic NEV market boom, China's new energy drive motor installations have achieved rapid growth in recent years. With 2021 domestic NEV sales exceeding 3.3 million units, assuming a dual-motor model penetration rate of 12%, domestic drive motor installations are projected to reach approximately 3.7 million units in 2021, representing a year-on-year growth exceeding 150%.
Amid favorable growth conditions for new energy vehicles, the global market size for new energy drive motors is projected to reach RMB 74 billion by 2025. Driven by multiple factors including dual credit policies, carbon emission regulations, and vehicle model advancements, the medium-to-long-term high-growth trajectory of new energy vehicle sales is increasingly certain. Long-range capabilities will become the mainstream trend for new energy vehicles. Global sales are forecasted at 9.25 million units in 2022, with China accounting for 5.3 million units; by 2025, global sales will exceed 22 million units, with China surpassing 9.45 million units; by 2030, the annual sales penetration rate of electric vehicles will approach 45%. In the medium to long term, the substitution of electric vehicles for fuel-powered vehicles will create a two-way feedback loop: positive feedback for electric vehicles, with more mature supporting systems and continuously improving user experience; while negative feedback from internal combustion engines leads to reduced supporting infrastructure and a declining user experience. Against this backdrop, new energy vehicles are poised to accelerate their replacement of traditional vehicles. Driven by rising downstream demand and the anticipated increase in dual-motor adoption spurred by future motor performance upgrades, the market for new energy drive motors is expected to enter a golden growth period.
